1. Field of the Invention
The present invention relates to a tape cartridge for accommodating a long printing tape on which a desirable series of characters are printed, a ribbon cartridge for accommodating an ink ribbon used for printing on the printing tape, and a printing device for detachably receiving the tape cartridge and the ribbon cartridge and printing the desirable series of characters on the printing tape.
2. Description of the Related Art
A printing tape generally accommodated in a tape cartridge is detachably and replaceably set in a printing device for printing a desirable series of letters and characters on the printing tape. Such a tape cartridge generally includes a mechanism for holding a long tape on a cylindrical tape core and feeding a required amount of the tape out of the tape core so as to efficiently accommodate the long tape and smoothly feed the tape to the printing device.
The printing device used with such a tape cartridge has a cutting mechanism for cutting the long tape to be desirable length. The cutting mechanism is typically arranged near a tape outlet to allow the long tape to be cut any desirable position through operation of a lever or the like.
An ink ribbon consumed for printing a desirable series of characters on a sheet or tape is also accommodated in an ink ribbon cartridge, which is detachably and replaceably set in the printing device. Such an ink ribbon cartridge generally includes a mechanism for holding a long ink ribbon on a cylindrical ink ribbon core and winding a used ink ribbon on a ribbon winding core so as to compactly accommodate the long ink ribbon and smoothly feed the ink ribbon to the printing device. Both the ink ribbon core and the ribbon winding core are formed to be rotatable via a driving mechanism formed in the printing device for driving and rotating the ink ribbon core and the ribbon winding core. This, the cartridge is not equipped the driving mechanism, effectively reduces the manufacturing cost of each expendable ink ribbon cartridge.
Under such a condition that the tape cartridge is not set in a printing device, the tape core unintentionally starts rotation due to some vibration or shock to press an end of the tape into a cartridge case. The end of the tape incidentally entering the cartridge case is not easily removed.
Although the cartridge case is to be opened for removal of the tape stuck in the cartridge case, forcible opening of the cartridge case generally accommodating both the tape and the ink ribbon may slacken the ink ribbon or even move the ink ribbon from a predetermined position to damage the whole cartridge.
When the tape cartridge having one end of the tape pressed into the cartridge case is accidentally set in a printing device, the tape held and fed between a platen and a printing head is stuck in the tape cartridge to damage the printing device.
Another problem arises in the printing device; that is, when the user tries to use a cutting mechanism during printing operation, the tape is not smoothly fed but may be stuck in the printing device.
There is also a problem in the ink ribbon cartridge. The ink ribbon core is rotated through engagement with a driving shaft of a driving element formed in the printing device as mentioned above. The ink ribbon core not being set in the printing device is thus easily rotatable due to vibration or shock so as to slacken the ink ribbon. Slack of the ink ribbon damages an ink ribbon driving mechanism of the printing device or lower the printing quality.
A protective sheet or element for interfering with rotation of the ink ribbon core is separately inserted in the ink ribbon core before delivery. Alternatively, a special casing for preventing slack of the ink ribbon is used during delivery and storage of the cartridge. These methods, however, have the following problems.
In the former method, manufacturing and management process of the cartridge is rather complicated, and the user should remove the protective sheet before use of the cartridge. When the user sets the cartridge in the printing device without removing the protective sheet, it may cause damage of the ink ribbon driving mechanism of the printing device.
In the latter method, for example, one or a plurality of engagement pawls are formed in an inner face of a special case for ribbon cartridge. The engagement pawls engage with the ink ribbon core and interfere with rotation of the ink ribbon core. This requires an additional manufacturing and management process to raise the cost of the expendable cartridge.
In such a cartridge, the ink ribbon and the tape are held between the platen and the printing head. When the user forcibly pulls out the tape under non-printing conditions, the ink ribbon joints the tape to be pulled out of the cartridge according to the forcible movement of the tape.